'Painted lady' butterfly migration hits Palo Alto

Thousands of 'painted lady' butterflies migrating to the Bay Area throughout this month

Thousands of painted lady butterflies are passing through Palo Alto and surrounding communities this month.

The mass of butterflies, which can be spotted at a rate of one every 10 seconds or more, typically migrate north in waves from desert areas along the U.S.-Mexico border. They can be seen in the early spring weeks through March, according to a website by scientists at University of California, Davis.

The butterflies, known by the scientific name Vanessa cardui, are about 1 1/2 inches to 2 1/4 inches wide. They are orange with a black, lacy pattern on the wings and a series of "eye spots" on the lower-lobe wings.

Northward-migrating painted ladies can travel the distance from Bishop to Davis in three days, surviving on yellow-fat reserves in their bodies, according to the Davis painted lady webpage.

The butterflies do not stop to feed or mate until they have burned up their reserves, carried over from the caterpillar stage. They fly in a straight line from southeast to northwet, like "bats out of Hell," and go over obstacles rather than trying to go around them, according to Davis researchers.

In 2005, the population was so dense that their numbers impeded traffic in desert regions, researchers said.

Recent sightings in Palo Alto have included a corridor between U.S. Highway 101 and El Camino Real and concentrations were seen around Edgewood Plaza Shopping Center.

Beginning in August, the movement reverses and butterflies head south toward the desert wintering grounds, according to the U.C. Davis website.

Comments

Like this comment

Posted by Simon
a resident of College Terrace
on Mar 27, 2009 at 10:14 am

Thanks for the report, Sue. We saw a ton flying by in our yard yesterday. What a treat!

Posted by b'fly enthusiast
a resident of Woodside
on Mar 27, 2009 at 3:49 pm

Several days ago, I noted a density of butterflies on woodside rd near hwy 101, but pulled off the road near crystal springs yesterday just to watch them. I didn't see one butterfly stop to nectar even though I was next to some beautiful lupine. They are on a mission. To me, they mostly seem to be flying from west to east. Has anyone else noted that?

To respond to b'fly enthusiast's question about the flight direction...

Where I was, they were going from slightly southeast to slightly northwest --- BUT, I think they were mostly following the vegetation that is forced in that immediate area to follow the direction of the road(s).

I was at the Menlo Park Library, off Alma Street, and they were following the vegetation alongside Alma (which goes northwest). They did start veering more directly north when the vegetation did so.

Posted by Victor
a resident of El Carmelo School
on Mar 28, 2009 at 8:26 am

I'll never forget -- 15 years ago or so when I was a kid at El Carmelo, it was recess and literally thousands of butterflies flew through the field. They would just brush up against you and fly on. Probably one of the most memorable and beautiful things I've ever seen.

Posted by Greg H.
a resident of another community
on Mar 28, 2009 at 3:10 pm

I'm in south San Jose, the Almaden Valley, just out in the country near Calero Reservoir. For hours and hours today, thousands upon thousands of these Painted Lady butterflies have been passing through, and not stopping for anything. They are still coming through. South to North. At any second in time you can look around you and count at least 20 of them cruising along. I walked a half my through the large grassy field next to our home and the butterflies were just as thick on the other side. It was a very wide migration, and I've never seen this many come through here since I've been living here for 26 years! Wonderful sight, a miracle!!

Posted by Sharon
a resident of Mountain View
on Mar 28, 2009 at 4:18 pm

I just got home from a trip to Gilroy Outlets and on our way home,at the highway 101 to 85 interchange we started seeing them. First I thought they were leaves then realized they were insects. I soon realized they were butterflies. They were very thick through the Almaden area, then thinned out in Saratoga. But when I got into Mountain View they got pretty thick again. I have been sitting here watching them out my window. I have lived in Mountain View 42 years and this is the first time I have ever seen this. It is amazing. The only sad part was that I ended up with quite a few of them on splatted on my windshield on my way home.

Posted by Jane D
a resident of another community
on Mar 28, 2009 at 5:16 pm

I am seeing the migration on the other side of the Penninsula. They are flying north through Milpitas and Fremont. Its really beautiful. I saw so many today in my neighborhood in Fremont and around the surrounding areas.

Posted by Greg H.
a resident of another community
on Mar 28, 2009 at 7:06 pm

To answer George in Morgan Hill. I read that they all migrate from south to north this time of year. They come all of the way up from the southwestern deserts regions: Arizona, New Mexico, Southern California and Northern Mexico, and migrate all of the way up to the great Northwest regions: Oregon, Washinton and British Columbia! They sure look to be in quite a hurry, with no stopping, and a good compass! Or is it follow the leader? Never have seen nearly this many!!

Posted by So cool
a resident of Green Acres
on Mar 28, 2009 at 11:41 pm

This afternoon (Sat 3/28), we saw so many butterflies crossing El Camino at Page Mill, we pulled over into the Palo Alto Square parking lot to watch. There were thousands of butterflies, it was like watching cherry blossoms flutter in the breeze. We drove back to Green Acres, and were surprised to find the butterflies all the way home. Even by Arastradero, there were dozens every few seconds, again like blossoms or leaves in the breeze. We watched for a long time, and the rate never slowed.

We never saw a single butterfly land on anything though. It was like they were on a mission. I wonder why they fly so low to the ground if they don't land? Seems kind of risky. They did fly over houses, but then would dip down low to the ground until they came up on another obstacle. Amazing how fast they can fly, too.

What a treat -- thanks for writing the article, I'm not sure we would have been paying attention otherwise, we might have just assumed we were seeing leaves blowing in the wind.

Posted by allieb
a resident of another community
on Mar 29, 2009 at 12:46 am

i saw a butterfly migration at the Pinnacles National Monument earlier this week (although not sure if they were painted ladies.) then what a wonderful surprise to see a migration of painted ladies flittering from one side of our street to the other, all afternoon! like others, i too, have never seen an organic event like this before- delightful!

Posted by Tom
a resident of another community
on Mar 29, 2009 at 4:40 pm

They're flying through Walnut Creek and Lafayette today. What made me google this (instead of just going "hmm, butterflies") was that there were a *lot* of them, and that they're all flying north. Fly on, butterfly, fly on!

Posted by b'fly enthusiast..again
a resident of Woodside
on Mar 29, 2009 at 8:16 pm

After watching the Painted Lady migration all week, I decided to try to get a few pix of them, if I could ever find them resting or nectaring. I grabbed my macro lens and headed off. I sat near a boggy area in a field today off 280 as they flew continually over my head. Finally, a few landed. After taking a few pix of several butterflies, I realized that they weren't Painted Ladies, but rather, Calif. Tortoiseshells. I did manage to photograph a few Painted Ladies, too. So, I am wondering if there are two migrations happening concurrently because I saw a lot of Tortoiseshell butterflies today. Anybody know?

Posted by Jenny
a resident of South of Midtown
on Mar 29, 2009 at 8:45 pm

I walked down Grove Street here in Palo Alto today and several butterflies passed me. They were rather dark in color so I presume they were the painted ladies. I would not have noticed them had I not read this report, thank you Sue.

Posted by Cardui
a resident of another community
on Mar 29, 2009 at 8:50 pm

Yes there is a simultaneous migration of Painted Ladies and California Tortoiseshells going on. Not just in the Bay Area, but across most of the State. Today I was in the Carson Pass/ Caples Lake / Kirkwood Ski Resort area (elevation 8,000 - 8,550 feet) and saw both Painted Ladies and California Tortoiseshells despite 40-42 degree temperatures and 8-10 feet of snow on the ground.

Posted by b'fly enthusiast
a resident of Woodside
on Mar 30, 2009 at 8:00 am

Thanks to V. cardui for the tortoiseshell migration confirmation. It must have been pretty extraordinary to see butterflies in the snow. I am currently reading about the difference between habitual dispersers and migrating species. Who knew? It's so interesting.

Dang! How lucky you all are. We worked in our yard outside all weekend and kept an eye out around town, didn't see a single butterfly! Of course I've seen them in the past on highways 152 and 5, but I haven't ever seen a migration in Palo Alto! Is it totally over now?

We saw these butterflies (or ones that look an awful lot like 'em) in Mammoth last week while skiing @ 10k ft! They really do go OVER obstacles and not around them! Now we're seeing them around our yard & in the park here in Palo Alto.

Posted by Resident
a resident of Palo Verde
on Mar 30, 2009 at 12:40 pm

I saw plenty of butterflies while walking around the neighborhood, but I saw none while I was doing yard work. I think you need to have your eyes watching around rather than concentrating on your own yards.

Posted by Suzan
a resident of another community
on Mar 30, 2009 at 1:10 pm

The painted lady butterflies have been migrating through our backyard here in Berryessa area of San Jose for almost a week now. Wasn't sure if it was a butterfly or a moth until I caught(and released)one yesterday and identified it using my insect book. Every 2 seconds another pair fly by. Only a few have stopped on the orange tree before taking off again. They are beautiful to see, but I just hope this doesn't mean an increase to damage in the gardens in the near future.

Posted by Nola
a resident of another community
on Mar 30, 2009 at 2:30 pm

Here in the east foothills of the Berryessa area of San Jose we've seen thousands every day flying through our ranch. I'm a native of Sunnyvale and have never seen these that I recall (at least as an adult). Very interesting and thank you for posting this. We wanted to know what was going on. Thank you!

Posted by Karen
a resident of another community
on Mar 30, 2009 at 3:20 pm

We saw them all weekend long passing through our yard. Occasionally, we saw pairs playing, but most where flying very rapidly going north. This is the first time I've noticed migrations in our area, it was really special to watch.

Posted by Scott
a resident of another community
on Mar 30, 2009 at 3:38 pm

Danville area yesterday off or sycamore valley road. 1000's of them. kids were very interested, caught a few for closer observation (and release) and yes all Painted Ladys. Very amazing site..and kids learned something today which was great experience for them 8 and 6 !

Posted by Greg H.
a resident of another community
on Mar 30, 2009 at 4:58 pm

They're still coming thru in droves down here in the countryside south of San Jose. It's been a few days now. It said in the San Jose Mercury and also in another article that they are on the move from the southern California deserts up to the Davis, CA area. So, disregard my earlier post saying they were heading all the way up to the northwest, I was misinfomed. Wow, there must be millions of them up there in Davis by now. Keep on truckin' you Painted Ladies, and watch out for those darn windshields!

Posted by esmeralda
a resident of East Palo Alto
on Mar 30, 2009 at 6:11 pm

thought i was nutty, but seeing the number of comments and reading up on painted ladies, whew!

i guess this is a treat. for a moment i thought that i had been spending too much time indoors if for the past 31 years i had never noticed this rite of spring. make sure you let everyone you know. many people haven't even noticed!!!!

Monday, March 30th... While driving north on E. Meadow after school today, and especially north of Middlefield (just as the article had said) I pointed these small little butterflies out to my son; all going in the same direction... and so quickly... it was amazing. I've only seen one in Barron Park. I just assumed this must happen every year, but according to several writers.. this is an unusual occurrence. Due to the color description in the article (and because I couldn't remember their name) I called them Mini Monarchs! The best way to view them is to be looking toward a solid mass of green leaved trees, then you see their bright sun-lit wings flickering as they fly. I made the analogy to my son of salmon swimming up against stream... driven to get home. You would think the birds must be having a feast, but I never saw one swoop down and catch one. We carefully picked one up on the road that was wobbling around. I knew it would die of the heat on the hot asphalt. It had the funniest big turned up 'nose'! We set it down in the grass and within a minute it flew away. The article said they would return... flying south in August... I hope they remember the way back through Palo Alto!

Posted by suesprops
a resident of another community
on Mar 31, 2009 at 1:21 pm

Hi I live in Clayton and they seem to be flying in after coming over the mountain from the south goig right down my street headed north. boy MT DIABLO must have been a challenge. go little butterflies!!!

Posted by Jayme Ringer
a resident of another community
on Mar 31, 2009 at 4:44 pm

I am from San Jose (north). I was driving on the 280 near Blk Mountain there were thousands of them flying...I felt badly as they hit my windshield. I had not heard of this migration...until a friend told me about it. What a wonderful scene of beauty. While driving along the 280 I noticed that there were more butterflies in the valley areas that were heavily wooded.

Question: When they migrate again to the South in August...will they pass by this way?

Posted by Becky
a resident of another community
on Apr 1, 2009 at 12:31 am

Tri-Valley (Pleasanton) What a treat the last several days!!! I've never seen anything like this - amazing! Up over the back neighbors fence - up over our two story house and so on ... all heading north. Out in traffic ... up over the cars ... Yikes - I wish they flew higher!

Posted by Norma
a resident of another community
on Oct 11, 2009 at 3:10 pm

I live in Campbell and would love to plant so that the Painted Ladies would have something when they come thru again. Any suggestions as to what I could plant so it would be blooming for them by Late Feb thru early April. Thanks